In the parent application, a simple and inexpensive pressure sealer is provided which is designed to handle business forms on a manual feed or semi-manual feed basis. While the invention in the parent application is entirely suitable for sealing small batches of documents by applying pressure to pressure sensitive adhesive strips, and while the invention of the parent application is extremely simple, according to the present invention it is desired to make a pressure sealer that is even simpler yet.
According to the present invention, a pressure sealer is provided that includes only one set of pressure applying rollers rather than two, as in the parent application. The bottom roller is driven by a reversible D.C. electric gear motor. The upper roller is biased by a spring into contact with the lower roller, and both rollers have a narrow periphery, typically less than about one inch, so that they apply a sealing force only at the pressure sensitive adhesive strips, not other parts of the business forms acted on by them. Sensors are also associated with the rollers, as well as a computer driver chip control, so as to effect braking and reverse rotation of the rollers once a form has passed almost completely through the nip, so that the form is acted upon by the sealing rollers twice to ensure a positive seal.
According to one aspect of the present invention, a pressure applying apparatus for applying pressure to business forms to activate pressure sensitive adhesive associated with the forms to seal one part of the form to another, comprises the following elements: A frame including a business form support surface. First and second narrow periphery rollers, rotatable about parallel first and second axes, and biased together to form a nip. Reversible drive means for driving at least one of the rollers alternately clockwise and counterclockwise. Sensor means for sensing the position of a business form supported by the business form support surface, the sensor means being positioned adjacent, but spaced from in the dimension of elongation of the support surface and perpendicular to the first and second axes, the nip. And, control means connected to the sensor means and the reversible drive means for driving a business form sensed by the sensor through the nip in a first direction along the support surface dimension of elongation so that a compressive sealing force is applied thereto, and after the business form has passed almost completely through the nip in the first direction, reversing the drive means to drive the business form through the nip again in a second direction,opposite the first direction.
The sensor means preferably comprises two sensor elements adjacent each other, a first sensor for initiating and controlling, with the control means, drive of the business form in the first direction, and a second sensor element, located closer to the nip than the first sensor, for initiating and controlling, with the control means, drive of the business form in the second direction. The sensors preferably are reflective sensors, while the drive means comprises a D.C. electric gear motor, and the control means comprises a computer drive chip. The first roller axis may be movably mounted, and the second roller axis stationarily mounted, with the first and second rollers biased together by spring biasing means acting on the first roller, with the electric motor connected only to the second roller. A form edge guide may extend perpendicular to the support surface and the roller axes, and adjacent the rollers and nip, to facilitate feeding of the forms into operative association with the rollers.
According to another aspect of the present invention a method of handling business forms, each having at least one strip of pressure sensitive adhesive of a predetermined width for affixing one part of each business form to another part, utilizing a machine having narrow width rollers which apply a sealing force at a nip, is provided. The method comprises the following steps: (a) Manually feeding a business form into operative association with the nip of the rollers, with at least one strip of adhesive aligned with the nip. (b) Rotating the rollers so that the business form is driven through the nip in a first direction, a sealing force being applied by the rollers only to the approximate area of the predetermined width of adhesive of the at least one adhesive strip. (c) Just prior to the form being driven completely through the nip, stopping the rollers, and reversing the direction of rotation thereof so that the business form is driven through the nip in a second direction, opposite the first direction. And, (d) after the business form has been driven through the nip in the second direction, manually removing it from operative association with the machine. Steps (b) and (c) are preferably practiced automatically. Typically the business form has a plurality of strips of pressure sensitive adhesive, and there are the further steps--after step (d)--of rotating the form to align a second strip of pressure sensitive adhesive with the rollers, and then repeating steps (a) - (d) for the second strip.
It is the primary object of the present invention to provide a simple pressure applying apparatus for sealing business forms with pressure sensitive adhesive, with a simple method of operation thereof. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.